1. Field of the Invention
The present invention relates to a document data management system for tracing the operation history of document data to which a code image is attached.
2. Description of the Related Art
As methods for getting an idea who has printed or duplicated (copied) printed matter or duplicated matter, there already exist various techniques. For example, according to Japanese Patent Laid-Open No. 2008-217340, when printing, identification information (ID) for distinguishing and identifying the printed matter from other printed matter is printed together and the ID and information for identifying a user who has provided instructions for printing (for example, a user's name etc.) are associated to each other and stored in a server. Because of this, it is possible to investigate who has printed the printed matter later. That is, by scanning the printed matter etc. through the use of a reading apparatus (scanner), the ID of the user is found and the user's name associated with the ID is read from the server and displayed, and thus it is possible to identify the printer who has printed the printed matter. Furthermore, when the printed matter is copied, the original ID is erased and a duplicated matter to which a new ID is attached instead is printed. At this time, information at the time of copying is added to the server. For example, it is defined that first a user A creates and prints document data and “1” is printed as an ID on the printed matter, and information “ID:1” and “printing user: A” is stored in the server. Then, when a user B copies the printed matter, “2” as a new ID is printed on the duplicated matter and information “ID:2”, “duplication user: B”, “ID:1→2” is added to the server. In this case, by scanning the duplicated matter, it is possible to grasp the fact that the duplicated matter is duplicated by the user B and also that the user A has first printed from the information “ID:1→2”.
According to the technique described in Japanese Patent Laid-Open No. 2008-217340, it is premised that the number of IDs obtained by scanning printed matter etc. is always one. However, in a practical operating scene of the technique for attaching a code image to a document for the purpose of managing document data, limiting duplication, etc., it can happen daily that two or more code images are detected by one-time scan. An example is shown below, in which two or more code images are detected by one-time scan.
First, a case where a plurality of documents is set on a document reading table at the same time is included. FIG. 10A shows a case where two documents are set on an image reading unit (scanner unit) of a multifunction peripheral. Reference numeral 1001 represents a pressure plate and plays a role in pressing the document from above so as to prevent it from moving at the time of a scan. Reference numeral 1002 represents a document reading table and a document 1003 and a document 1004 both of A4 size to which a code image is attached, respectively, are placed and set in a state where they look like one A3 size sheet. The broken line indicates the printed position of the code image on each document. In this state, if a user provides operation instructions for copying, the two documents are scanned at the same time and one piece of image data is acquired, and thus, from the image data, two code images are detected.
Next, a case where two or more code images are attached originally to a document to be scanned is included. FIG. 10B shows an example of a document to which code images (QR codes) are attached to two positions, that is, the top-left corner and the top-right corner. Normally, one QR code is attached to one document and for example, when it is copied, the position to which a QR code is attached on the document to be copied and output (hereinafter referred to as a “duplicated document”) is the position to which the QR code is attached on the document to be copied (hereinafter, referred to as an “original document”). That is, as a general rule, the QR code on the duplicated document is the QR code attached to the original document, the information of which is updated. However, when the document is set on the document reading table in an inclined state or the QR code is stained, there may be a case where the QR code is not detected correctly or decoding fails even if it is detected correctly. As a result, the QR code on the original document is recognized as just a figure and a new QR code may be attached separately to the duplicated document. FIG. 10B shows a duplicated document 1005 output in such circumstances and there exist a QR code 1006 on the original document, which has been recognized as a figure, and a QR code 1007 attached separately as a new code image.
The case where two or more image codes are detected in one-time scan as described above is not at all taken into consideration in the technique in Japanese Patent Laid-Open No. 2008-217340. That is, there is not at all a description on how to manage information in a case where a plurality of code images is detected as a result of a scan of a document at the time of copying and such circumstances occur where there exists a plurality of pieces of information, such as an ID of the document, and thus such a case has not been able to be dealt with.